dev/parport: fix the array out-of-bounds risk

Fixed array out-of-bounds issues caused by sprintf
by replacing it with snprintf for safer data copying,
ensuring the destination buffer is not overflowed.

Below is the stack trace I encountered during the actual issue:

[ 66.575408s] [pid:5118,cpu4,QThread,4]Kernel panic - not syncing: stack-protector:
Kernel stack is corrupted in: do_hardware_base_addr+0xcc/0xd0 [parport]
[ 66.575408s] [pid:5118,cpu4,QThread,5]CPU: 4 PID: 5118 Comm:
QThread Tainted: G S W O 5.10.97-arm64-desktop #7100.57021.2
[ 66.575439s] [pid:5118,cpu4,QThread,6]TGID: 5087 Comm: EFileApp
[ 66.575439s] [pid:5118,cpu4,QThread,7]Hardware name: HUAWEI HUAWEI QingYun
PGUX-W515x-B081/SP1PANGUXM, BIOS 1.00.07 04/29/2024
[ 66.575439s] [pid:5118,cpu4,QThread,8]Call trace:
[ 66.575469s] [pid:5118,cpu4,QThread,9] dump_backtrace+0x0/0x1c0
[ 66.575469s] [pid:5118,cpu4,QThread,0] show_stack+0x14/0x20
[ 66.575469s] [pid:5118,cpu4,QThread,1] dump_stack+0xd4/0x10c
[ 66.575500s] [pid:5118,cpu4,QThread,2] panic+0x1d8/0x3bc
[ 66.575500s] [pid:5118,cpu4,QThread,3] __stack_chk_fail+0x2c/0x38
[ 66.575500s] [pid:5118,cpu4,QThread,4] do_hardware_base_addr+0xcc/0xd0 [parport]

Signed-off-by: tuhaowen <tuhaowen@uniontech.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20240708080430.8221-1-tuhaowen@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/parport/procfs.c b/drivers/parport/procfs.c
index bd388560ed59267f785fd90794dc8c78ddb51bc9..c2e371c50dcfa5e1ca03983003aa27cbe729bf1a 100644 (file)
--- a/drivers/parport/procfs.c
+++ b/drivers/parport/procfs.c
@@ -51,12 +51,12 @@ static int do_active_device(struct ctl_table *table, int write,
        
        for (dev = port->devices; dev ; dev = dev->next) {
                if(dev == port->cad) {
-                       len += sprintf(buffer, "%s\n", dev->name);
+                       len += snprintf(buffer, sizeof(buffer), "%s\n", dev->name);
                }
        }
 
        if(!len) {
-               len += sprintf(buffer, "%s\n", "none");
+               len += snprintf(buffer, sizeof(buffer), "%s\n", "none");
        }
 
        if (len > *lenp)
@@ -87,19 +87,19 @@ static int do_autoprobe(struct ctl_table *table, int write,
        }
        
        if ((str = info->class_name) != NULL)
-               len += sprintf (buffer + len, "CLASS:%s;\n", str);
+               len += snprintf (buffer + len, sizeof(buffer) - len, "CLASS:%s;\n", str);
 
        if ((str = info->model) != NULL)
-               len += sprintf (buffer + len, "MODEL:%s;\n", str);
+               len += snprintf (buffer + len, sizeof(buffer) - len, "MODEL:%s;\n", str);
 
        if ((str = info->mfr) != NULL)
-               len += sprintf (buffer + len, "MANUFACTURER:%s;\n", str);
+               len += snprintf (buffer + len, sizeof(buffer) - len, "MANUFACTURER:%s;\n", str);
 
        if ((str = info->description) != NULL)
-               len += sprintf (buffer + len, "DESCRIPTION:%s;\n", str);
+               len += snprintf (buffer + len, sizeof(buffer) - len, "DESCRIPTION:%s;\n", str);
 
        if ((str = info->cmdset) != NULL)
-               len += sprintf (buffer + len, "COMMAND SET:%s;\n", str);
+               len += snprintf (buffer + len, sizeof(buffer) - len, "COMMAND SET:%s;\n", str);
 
        if (len > *lenp)
                len = *lenp;
@@ -117,7 +117,7 @@ static int do_hardware_base_addr(struct ctl_table *table, int write,
                                 void *result, size_t *lenp, loff_t *ppos)
 {
        struct parport *port = (struct parport *)table->extra1;
-       char buffer[20];
+       char buffer[64];
        int len = 0;
 
        if (*ppos) {
@@ -128,7 +128,7 @@ static int do_hardware_base_addr(struct ctl_table *table, int write,
        if (write) /* permissions prevent this anyway */
                return -EACCES;
 
-       len += sprintf (buffer, "%lu\t%lu\n", port->base, port->base_hi);
+       len += snprintf (buffer, sizeof(buffer), "%lu\t%lu\n", port->base, port->base_hi);
 
        if (len > *lenp)
                len = *lenp;
@@ -155,7 +155,7 @@ static int do_hardware_irq(struct ctl_table *table, int write,
        if (write) /* permissions prevent this anyway */
                return -EACCES;
 
-       len += sprintf (buffer, "%d\n", port->irq);
+       len += snprintf (buffer, sizeof(buffer), "%d\n", port->irq);
 
        if (len > *lenp)
                len = *lenp;
@@ -182,7 +182,7 @@ static int do_hardware_dma(struct ctl_table *table, int write,
        if (write) /* permissions prevent this anyway */
                return -EACCES;
 
-       len += sprintf (buffer, "%d\n", port->dma);
+       len += snprintf (buffer, sizeof(buffer), "%d\n", port->dma);
 
        if (len > *lenp)
                len = *lenp;
@@ -213,7 +213,7 @@ static int do_hardware_modes(struct ctl_table *table, int write,
 #define printmode(x)                                                   \
 do {                                                                   \
        if (port->modes & PARPORT_MODE_##x)                             \
-               len += sprintf(buffer + len, "%s%s", f++ ? "," : "", #x); \
+               len += snprintf(buffer + len, sizeof(buffer) - len, "%s%s", f++ ? "," : "", #x); \
 } while (0)
                int f = 0;
                printmode(PCSPP);